Department of Aquatic Animal Diseases, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa 16059, Turkey.
Microbiologia, Departament de Biologia, Edifici Guillem Colom, Universitat de les Illes Balears, Campus UIB, 07122 Palma de Mallorca, Spain; Institut Mediterrani d'Estudis Avançats (IMEDEA, CSIC-UIB), Campus UIB, 07122 Palma de Mallorca, Spain.
Syst Appl Microbiol. 2024 Nov;47(6):126552. doi: 10.1016/j.syapm.2024.126552. Epub 2024 Sep 19.
Pseudomonas species constitute a significant group of pathogens in aquarium fish and frequently cause haemorrhagic septicaemia. This study conducted a taxonomic characterization of Pseudomonas isolates from aquarium fish exhibiting deep ulceration and general disease signs. A polyphasic approach was employed to ascertain the taxonomic affiliation of the strains. The overall genome relatedness indices of digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) between the strains and the other members of the genus Pseudomonas were found to be below the established thresholds of 70 and 95-96%, respectively. Whole-genome based phylogenetic analysis revealed that strains 119P and 120P were closely related to P. arcuscaelestis. Strain 137P was related to P. peradeniyensis, while strains 147P and 148P were closely related to P. japonica. The morphological, physiological, and biochemical characteristics of the strains and the genome relatedness indices of dDDH and ANI below the established thresholds confirmed the classification of the strains as three novel species. Genome analyses of the strains were also conducted to determine their biosynthesis-related gene clusters, virulence features and ecological distribution patterns. Based on polyphasic characterization, the strains 119P, 120P, 137P, 147P, and 148P are novel species within the genus Pseudomonas, for which the following names are proposed: Pseudomonas auratipiscis sp. nov., with the strain 119P as the type strain (=DSM 117162 , =LMG 33381); Pseudomonas carassii sp. nov., with the strain 137P as the type strain (=DSM 117060, =LMG 33378); and Pseudomonas ulcerans sp. nov. 147P, as the type strain (=DSM 117163, =LMG 33377).
假单胞菌属是鱼类水族馆中重要的病原体群，经常引起出血性败血症。本研究对表现出深度溃疡和一般疾病症状的水族馆鱼类中的假单胞菌分离株进行了分类特征描述。采用多相方法确定菌株的分类归属。菌株与假单胞菌属其他成员之间的全基因组相关指数数字 DNA-DNA 杂交（dDDH）和平均核苷酸同一性（ANI）分别低于 70%和 95-96%的既定阈值。全基因组系统发育分析表明，菌株 119P 和 120P 与 P. arcuscaelestis 密切相关。菌株 137P 与 P. peradeniyensis 相关，而菌株 147P 和 148P 与 P. japonica 密切相关。菌株的形态、生理和生化特征以及低于既定阈值的 dDDH 和 ANI 全基因组相关指数证实了这些菌株被分类为三个新种。还对这些菌株的基因组进行了分析，以确定它们的生物合成相关基因簇、毒力特征和生态分布模式。基于多相特征，菌株 119P、120P、137P、147P 和 148P 是假单胞菌属的新种，建议采用以下名称：金黄假单胞菌，以菌株 119P 为模式菌株（=DSM 117162，=LMG 33381）；拟态假单胞菌，以菌株 137P 为模式菌株（=DSM 117060，=LMG 33378）；以及溃疡假单胞菌 147P，作为模式菌株（=DSM 117163，=LMG 33377）。
